#include <bits/stdc++.h>
#define int long long
using namespace std;
int const mxN = 2e5+5;
int const mxR = 505;
vector<int> adj [mxN];
int in[mxN], out[mxN], t, r , n, region[mxN], q;
vector<pair<int,int>> reg [mxR];
int ans [mxR][mxR], cnt[mxR];
void dfs ( int i, int p ) {
for(int j=1; j<=r; j++) {
if(region[i]==j) continue;
ans[j][region[i]] += cnt[j];
}
cnt[region[i]]++;
for(auto it:adj[i]){
if(it==p) continue;
dfs(it,i);
}
cnt[region[i]]--;
}
signed main() {
ios_base:: sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin>>n>>r>>q>>region[1];
for(int i=2; i<=n; i++) {
int k, h; cin>>k>>h;
adj[i].push_back(k), adj[k].push_back(i);
region[i] = h;
}
dfs(1,0);
for(int i=0; i<q; i++) {
int x,y; cin>>x>>y;
cout<<ans[x][y]<<endl;
}
return 0;
}
